Make chili:
Heat 3 tablespoons oil in a 5- to 6-quart heavy pot over moderately high heat until hot but not smoking, then brown beef in 4 batches, stirring occasionally, about 4 minutes per batch, transferring with a slotted spoon to a bowl.
Add remaining tablespoon oil to pot and sauté onion and jalapeños over moderately high heat, stirring, until onion is softened, about 4 minutes. Reduce heat to moderate, then add garlic, cocoa powder, salt, and spices and cook, stirring, 1 minute. Return beef to pot with any juices that have accumulated in bowl and stir in tomatoes, corn, and water. Simmer chili, uncovered, stirring occasionally, until meat is very tender, 1 1/4 to 1 1/2 hours.
Remove from heat and stir in beans, olives, cilantro, and salt to taste. Transfer chili to a shallow 3-quart baking dish.

Make topping:
Preheat oven to 400°F.
Whisk together flour, cornmeal, cheese, sugar, baking powder, salt, cumin, cilantro, and jalapeño in a large bowl.
Whisk together milk, butter, and egg in a small bowl, then stir into flour mixture until just combined.
Drop batter by large spoonfuls (about 8) over chili, spacing them evenly, and bake in middle of oven 10 minutes. Reduce temperature to 350°F and bake pie until topping is cooked through, about 30 minutes more.

Note: Chili can be made 1 day ahead and cooled, uncovered, then chilled, covered.